THE EARTH will reach temperatures not fit for human survival in just a few decades, according to scientists who predict nine catastrophes are coming as part of what they call Hothouse Earth.

Climate change will see temperatures rise 4C-5C higher than regular temperatures causing a "severe risks for health, economies, political stability, and ultimately, the habitability of the planet for humans”.

The doomsday warning comes from a team of international university researchers, who said global targets to keep temperatures from rising 2C are not tough enough to stop what is coming.

Writing in the journal Proceedings of the National Academy of Sciences, scientists said a Hothouse Earth would lead to rising sea levels, increased methane and carbon dioxide and melting permafrost.

Professor Johan Rockstrom, a leading member of the research team from the University of Stockholm, Sweden, said several "tipping points" will act as like a "row of dominoes", occurring one after the other and posing catastrophic risk to climate change.

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The team of scientists wrote: "Our analysis suggests that the Earth system may be approaching a planetary threshold that could lock in a continuing rapid pathway toward much hotter conditions - Hothouse Earth.

"This pathway would be propelled by strong, intrinsic, biogeophysical feedbacks difficult to influence by human actions, a pathway that could not be reversed, steered or substantially slowed.

"Where such a threshold might be is uncertain, but it could be only decades ahead at a temperature rise of (around) 2C above pre-industrial."

The only way to avoid a potential Hothouse Earth would be an active approach by scientists and environmentalists, to take "deep cuts" towards reducing greenhouse gas emissions as well as removing carbon dioxide from the atmosphere using technological advancements.

Greenhouse gas emissions will rise as stored carbon from beneath the earth will be released (Image: GETTY)

Climate researcher Dr Phil Williamson, from the University of East Anglia, said: "In the context of the summer of 2018, this is definitely not a case of crying wolf, raising a false alarm.

"The wolves are now in sight."

Speaking about the impact of climate change, Chris Rapley, Professor of Climate Science at University College London said: "Previous research has shown that an increase in the mean global temperature of 11-12C would make more than half of the land area currently occupied by humans uninhabitable.

"So, a 'runaway' warming to a new and uncontrollable hot state would represent an existential threat to humanity and the majority of existing species."